有机磁性膨润土对环丙沙星和四环素的吸附性能  

Adsorption of ciprofloxacin and tetracycline by organically modified magnetic bentonite

作　　者：汤睿 张寒冰 陆彩妹 刘坤 王忠凯 余思珊 童张法[1,3] 季军荣 TANG Rui;ZHANG Hanbing;LU Caimei;LIU Kun;WANG Zhongkai;YU Sishan;TONG Zhangfa;JI Junrong(Guangxi Colleges and Universities,Key Laboratory of New Technology and Application in Resource Chemical Engineering,School of Chemistry and Chemical Engineering,Guangxi University,Nanning 530004,Guangxi,China;College of Resources,Environment and Materials,Guangxi University,Nanning 530004,Guangxi,China;Guangxi Engineering Academy of Calcium Carbonate Industrialization,Guangxi University,Nanning 530004,Guangxi,China;Guangxi Cooperative Innovation Centre for Calcium-based Materials(GCICCM),Chongzuo South Cement Co.,Ltd.,Chongzuo 532200,Guangxi,China)

机构地区：[1]广西大学化学化工学院,资源化工应用新技术广西高校重点实验室,广西南宁530004 [2]广西大学资源环境与材料学院,广西南宁530004 [3]广西大学,广西碳酸钙产业化工程院,广西南宁530004 [4]崇左南方水泥有限公司,广西钙基材料协同创新中心,广西崇左532200

出　　处：《化工进展》2021年第11期6235-6245,共11页Chemical Industry and Engineering Progress

基　　金：国家自然科学基金(21576055);广西石化资源加工及过程强化技术重点实验室主任课题(2020Z008)。

摘　　要：为了提高磁性膨润土(magnetic bentonite,MB)的磁分离性能,达到高效去除抗生素的目的,本文采用羧甲基纤维素(sodium carboxymethyl cellulose,CMC)和壳聚糖(chitosan,CS)相互作用所生成的有机共聚膜(chitosan/sodium carboxymethyl cellulose copolymer film,CC)对MB进行联合修饰,制得双有机修饰的有机磁性膨润土(magnetic bentonite/carboxymethyl cellulose-chitosen composite,MB-CC),同时进行了MB-CC对环丙沙星(ciprofloxacin,CIP)和四环素(tetracyclines,TC)的吸附性能研究。表征结果表明,磁性Fe_(3)O_(4)纳米粒子和有机共聚膜CC成功地固定在MB上;经过CC改性,提高了Fe_(3)O_(4)的稳定性和对CIP及TC的去除性能。吸附结果表明,在pH为5、温度为25℃的条件下,MB-CC对CIP和TC的吸附容量(182mg/g和189mg/g)高于MB对CIP和TC的吸附容量(147mg/g和136mg/g)。经过5次循环,MB-CC对CIP和TC的去除率仍然保持在90%以上。与Freundlich模型相比较而言,CIP和TC在MB和MB-CC上的吸附行为更加符合Langmuir模型;吸附过程可由准二级动力学模型描述,说明吸附速率主要由化学吸附控制。MB-CC对CIP和TC的吸附机理主要包括孔扩散、阳离子交换和静电吸引作用。综上所述,MB-CC具有合成简单、高效等优点,是一种很有前途的抗生素废水去除方法。In order to endow magnetic bentonite(MB)with magnetic separation ability and simultaneously obtain stronger removal capacity of antibiotics,magnetic bentonite/carboxymethylcellulose-chitosan composite(MB-CC)was prepared by modifying previously fabricated MB with carboxymethylcellulose(CMC)and chitosan(CS).The characterization of both MB-CC and MB and their adsorption properties towards ciprofloxacin(CIP)and tetracycline(TC)in aqueous solution were investigated.Textural characterization results revealed that the magnetic nanoparticles(Fe_(3)O_(4))were successfully immobilized onto bentonite and further modified with CC.The surface functionalization with CC concurrently enhanced the stability of Fe_(3)O_(4) and removal capability of CIP and TC for the final product.Adsorption results indicated that MB-CC exhibited superior adsorption performance for CIP and TC(182mg/g and 189mg/g)to MB(147mg/g and 136mg/g)at pH 5.0 and 25℃.Adsorptive removal of CIP and TC by MB-CC was more than 90%even after 5 cycles of adsorption-desorption process.The adsorption isotherms were better described by Langmuir model than Freundlich model.The adsorption process fitted well with pseudosecond order kinetic model,indicating that the rate-determining step for MB-CC was chemical adsorption.The main steps during the successful adsorption process of MB-CC for CIP and TC included pore diffusion,ions exchange and electrostatic interaction.The current approach is credited to the simplified synthesis and high-efficiency of MB-CC which could also be deemed as a promising alternative sorbent for removal antibiotics from wastewater.

关 键 词：磁性膨润土 有机修饰 吸附 环丙沙星 四环素 

分 类 号：X703[环境科学与工程—环境工程]